From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752884Ab3FXQuw (ORCPT ); Mon, 24 Jun 2013 12:50:52 -0400 Received: from smtp.citrix.com ([66.165.176.89]:27518 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752520Ab3FXQuu (ORCPT ); Mon, 24 Jun 2013 12:50:50 -0400 X-IronPort-AV: E=Sophos;i="4.87,929,1363132800"; d="scan'208";a="33083380" Date: Mon, 24 Jun 2013 17:50:46 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Stefano Stabellini CC: Chen Gang , Catalin Marinas , Will Deacon , Tony Lindgren , "olof@lixom.net" , Santosh Shilimkar , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Linux-Arch Subject: Re: [Suggestion] arch: arm64: xen: "ln -s" the paravirt.h from arm. In-Reply-To: Message-ID: References: <51C53C06.7050205@asianux.com> <51C81115.4070803@asianux.com> <51C81A39.5060909@asianux.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 24 Jun 2013, Stefano Stabellini wrote: > On Mon, 24 Jun 2013, Chen Gang wrote: > > Hello Maintainers: > > > > if 'CONFIG_XEN' > > > > CC arch/arm64/xen/../../arm/xen/enlighten.o > > arch/arm64/xen/../../arm/xen/enlighten.c:19:26: fatal error: asm/paravirt.h: No such file or directory > > > > The related .config file for next-20130624 is in attachment. > > > > > > If "ln -s ../../../arm/include/asm/paravirt.h paravirt.h", it can pass > > compiling, but I do not know how to make a patch for it ("ln -s ..."), > > Do we have another more suitable ways for it (or another fixing ways) ? > > > > Welcome any suggestions or completions. > > The problem is caused by: > > commit 3a885582a366caf868b0782041c44854ff4c3568 > Author: Stefano Stabellini > Date: Wed May 29 10:56:34 2013 +0000 > > xen/arm: account for stolen ticks > > that is in my tree for linux-next (even though I have not received any > replies from the ARM maintainers so I don't know when and if it is going > to go upstream). > > I think that the best thing to do would be to add a couple of ifdef > CONFIG_PARAVIRT in arch/arm/xen/enlighten.c. I'll add them to my tree. Actually now that we have XEN support under arm64, we can just introduce the same pv_time_op struct and paravirt header that this patch http://marc.info/?l=linux-arm-kernel&m=136992435301890&w=2 is introducing under arm. Any opinions? --- diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 19c1cde..47bd26b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -207,6 +207,25 @@ config FORCE_MAX_ZONEORDER default "14" if (ARM64_64K_PAGES && TRANSPARENT_HUGEPAGE) default "11" +config PARAVIRT + bool "Enable paravirtualization code" + ---help--- + This changes the kernel so it can modify itself when it is run + under a hypervisor, potentially improving performance significantly + over full virtualization. + +config PARAVIRT_TIME_ACCOUNTING + bool "Paravirtual steal time accounting" + select PARAVIRT + default n + ---help--- + Select this option to enable fine granularity task steal time + accounting. Time spent executing other tasks in parallel with + the current vCPU is discounted from the vCPU power. To account for + that, there can be a small performance impact. + + If in doubt, say N here. + config XEN_DOM0 def_bool y depends on XEN @@ -214,6 +233,7 @@ config XEN_DOM0 config XEN bool "Xen guest support on ARM64 (EXPERIMENTAL)" depends on ARM64 && OF + select PARAVIRT help Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. diff --git a/arch/arm64/include/asm/paravirt.h b/arch/arm64/include/asm/paravirt.h new file mode 100644 index 0000000..54e895b --- /dev/null +++ b/arch/arm64/include/asm/paravirt.h @@ -0,0 +1,19 @@ +#ifndef _ASM_ARM64_PARAVIRT_H +#define _ASM_ARM64_PARAVIRT_H + +struct static_key; +extern struct static_key paravirt_steal_enabled; +extern struct static_key paravirt_steal_rq_enabled; + +struct pv_time_ops { + unsigned long long (*steal_clock)(int cpu); +}; +extern struct pv_time_ops pv_time_ops; + +static inline u64 paravirt_steal_clock(int cpu) +{ + return pv_time_ops.steal_clock(cpu); +} + + +#endif diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 7b4b564..17613ad 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -18,6 +18,7 @@ arm64-obj-$(CONFIG_SMP) += smp.o smp_spin_table.o smp_psci.o arm64-obj-$(CONFIG_HW_PERF_EVENTS) += perf_event.o arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)+= hw_breakpoint.o arm64-obj-$(CONFIG_EARLY_PRINTK) += early_printk.o +arm64-obj-$(CONFIG_PARAVIRT) += paravirt.o obj-y += $(arm64-obj-y) vdso/ obj-m += $(arm64-obj-m) diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c new file mode 100644 index 0000000..53f371e --- /dev/null +++ b/arch/arm64/kernel/paravirt.c @@ -0,0 +1,25 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Copyright (C) 2013 Citrix Systems + * + * Author: Stefano Stabellini + */ + +#include +#include +#include +#include + +struct static_key paravirt_steal_enabled; +struct static_key paravirt_steal_rq_enabled; + +struct pv_time_ops pv_time_ops; +EXPORT_SYMBOL_GPL(pv_time_ops);